For example, a configuration described in Patent Document 1 is known as such a type of vibration prevention device. This vibration prevention device includes a tubular first attachment member that is connected to one of a vibration source and a vibration receiver, a second attachment member that is connected to the other thereof, an elastic body that connects two attachment members to each other, and a partition member that partitions a liquid chamber in the first attachment member having a liquid enclosed therein into a first liquid chamber and a second liquid chamber. The vibration prevention device also includes a first limiting passage and a second limiting passage that cause the two liquid chambers to communicate with each other, a cylinder chamber that is disposed between the two liquid chambers, and a plunger member that is disposed to be movable between an opened position and a closed position in the cylinder chamber.
A plurality of types of vibration having different frequencies such as idle vibration or shake vibration are input to the vibration prevention device. Accordingly, in the vibration prevention device, resonance frequencies of the first limiting passage and the second limiting passage are set (tuned) to frequencies of the different types of vibration. By moving the plunger member between the opened position and the closed position depending on the frequency of input vibration, a limiting passage in which a liquid flows is switched between the first limiting passage and the second limiting passage.